Electrical socket connectors and other electrical contact devices



Sept. 5, 1967 s. T DEAKIN 3,340,491 ELECTRICAL SOCKET CONNECTORS ANDOTHER ELECTRICAL CONTACT DEVICES Filed April 17, 1964 2 Sheets-Sheet 1INVENTOR. STAN LEY THOMAS DEAKI N yQmZ i 4 HIS ATTORNEY.

Sept. 5, 1967 s. T DEAKIN 3,340,491

ELECTRICAL SOCKET CONNECTORS AND OTHER ELECTRICAL CONTACT Filed April17, 1964 DEVICES 2 Sheets-Sheet I 4 -I II INVENTOR STAN L EY THOMAS DEAKIN BY 4 K dodg HIS ATTORNEY.

United States Patent 3 340 491 ELECTRICAL SOCKEFCOIVNECTORS AND OTHERELECTRICAL CONTACT DEVICES Stanley Thomas Deakin, Walton-on-Thames,Surrey, Eng- 7 The invention relates to electrical socket connectors,plug, switches and other electrical contact devices of the kind having abody (e.g. of plate or disc form) of insulating material carrying atleast one electric contact which, in use, makes pressure or slidingengagement with a co-operating contact. The invention is particularly,but not exclusively, concerned with electrical socket connectors of thekind having a support body or plate of insulating material, a pluralityof sockets in the support body for receiving the pins or wires of atransistor, valve or other electrical plug, each socket having means formaking an electrical connection with the pin or Wire. The invention isespecially applicable to such devices of small size. The invention alsorelates to a method of making such devices.

It is an object of the invention to provide various improvements indevices of the above kind and in the manufacture thereof.

The invention provides an electrical contact device of the above kind inwhich the contact is provided by a metallic coating on the body.

The device may have a separately constructed resilient contact securedto the body and opposed to the coated contact to receive and gripbetweenthem a separating con-tact. Preferably the resilient contact iswelded or soldered to a metallic coating on the body which may be apart, or an extension, of the coated contact.

When the invention is applied to a socket connector,

the body may be of glass with a socket or sockets etched therein andcoated with metal to provide socket contact surfaces.

The invention also provides the method of making an electrical socketconnector which comprises the steps of exposing to light selectedportions of a body of photosensitive glass to render the body morereadily soluble by etching acid in the region where a socket isrequired, etching the body to form the socket and coating with metal theinternal surface of the socket and an area of the external surface ofthe body extending from the mouth of the socket.

The photo-sensitive glass used is preferably of the kind in which theetching rate of exposed portions is greater than the etching rate ofunexposed portions or vice versa and it may be of the kind sold by theComing Glass Works under the trade name Fotoform. After the sockets havebeen formed, the glass may be converted to its ceramic form. Theexposure may be eflected through a negative, or a positive, of thedesired socket pattern.

The invention further provides the method of making a multi-socketelectrical socket connector which comprises the steps of exposing tolight selected portions of a body of photo-sensitive glass to render thebody more readily soluble. by etching acid in the regions where socketsare required, etching the body to form the sockets, forming on the bodymetallic coatings lining the sockets and extending from the socketsindividually over portions of the external surface of the body, weldingor soldering to the coatings on the'external surface of the body a sheetmetal unit shaped to comprise a multiplicity of resilient contacts, onefor each socket, joined together by narrow ties, inserting portions ofthe contacts into the sockets and cutting the ties to separate thecont-acts.

Patented Sept. 5, 1967 The metal coating may be applied by thetechniques ware) and it may be applied to the whole surface of the bodyand the unwanted areas removed by etching or it may be applied (e.g. bya silk screen printing operation) to the wanted areas only. To coatinternal (i.e. socket faces) bores, a metallic paste may be carried intothe bores on pins and surplus removed by suction. The paste is heatedafter application as practiced in the art aforesaid.

The method may, in addition, include the steps of inserting a springcontact strip into the sockets, said strip having an extensionprojecting from the socket and overlying the metallic coating on theexternal surface of the glass body and securing the extension to thecoating.

The contact strips or the contact unit may be produced by etching fromsheet metal.

Thus the spring contacts may be constructed by a method which comprisesfirst forming a unit by etching a sheet of metal to provide a blank inthe form of a continuous ring which internally is conveniently, but notnecessarily, larger than the support plate, and a number selves to makeelectrical connection with the wires or pins of a plug inserted into thesockets and to urge these wires or pins into electrical contact with themetallic linings of the sockets.

The connector may comprise a stack of such support plates each arrangedas described above and each having the same number and arrangement ofsockets, there being several through sockets in the stack each of whichis provided by corresponding sockets in the several support plates, oneof which corresponding sockets is internally coated has a spring and ametal strip extending to the periphery of the support plate, the socketso provided being in diiferent plates for the different through sockets,whereby some pins or wires of an electrical plug connect with onesupport plate of the stack and some with another support plate of thestack. This arrangement enables the ends of the metal strips to bespaced apart axially of the stack as well as around the periphery of thesupport plates.

Some specific examples of electrical socket connectors according to theinvention and a modifications thereto will now be described withreference to the accompanying diagrammatic drawings in which:

FIGURE 1 is an exploded perspective view of the first connector showinghow the connector is constructed,

FIGURE 2 is a plan view of the blank from which the spring contactstrips are made,

FIGURE 3 is a perspective view of a second connector with the coverplate removed,

FIGURE 4 is a section through a modified connector,

FIGURE 5 is a perspective view showing another form of socket connectorwith its associated plug,

FIGURE 6 shows a contact unit from which the resilient contacts ofFIGURE 5 are produced,

FIGURE 7 shows, in perspective, a further form of connector,

FIGURE 8 shows the form of plug to be used with the connector of FIGURE7,

FIGURE 9 is a cross-section, on the line 99, through the connector ofFIGURE 7 in position in a panel,

FIGURE '10 is a cross-section on the line 1010 in FIGURE 7, and

FIGURE 11 shows a portion of the contact unit used in the constructionof the connector of FIGURE 7.

As can be seen from FIGURE 1 the first embodiment of an electricalsocket connector comprises an annular support plate or body providing aring of sockets 11. The support plate 10 is made from photo-sensitivesheet or plate glass which is sold under the trade name Fotoform. Thesockets 11 are made by masking the photosensitive glass with a negativeof the desired socket pattern, and exposing the masked glass toultra-violet light. The portions of the glass which have not beenexposed are very much more readily etched than the exposed portions (thesolubility ratio of unexposed to exposed portions in hydrofluoric acidis about :1) and when the negative has been removed the selectivelyexposed glass is immersed in hydrofluoric acid to etch away the exposedglass to form the sockets. The glass is then converted to its ceramicform.

The next stage in the manufacture is to produce metal coatings onselected areas of the support plate 10, these areas being the insides ofthe sockets and strips 12 extending from the individual sockets to theedge of the plate. The metal (e.g. copper) is applied as a paste andsubsequently sintered, as in the decoration of ceramic wares. The pasteis carried into the sockets on pins, any surplus being removed by vacuumand is applied either as strips 12 using a silk screen printingtechnique or over the whole area of the plate, the metal between thestrips subsequently being removed by photo-etching.

The next stage is to produce the blank shown in FIG- URE 2 from a sheetof rhodium plated beryllium copper or beryllium nickel. This is done byetching from sheet material using a photo-sensitive resin resist and amaster negative. If desired the inner ends of the arms may be connectedto a central ring, subsequently removed.

The blank shown in FIGURE 2 comprises an annular ring 14 with arms 15extending inwardly from the ring 14. Each arm 15 has to be bent to theshape shown in FIGURE 1 with a portion 16 to overlie the metal strip 12-and a spring arm 17 bent downwardly from the portion 16 to lie insidethe socket 11.

The step of bending the spring arm 17 downwardly can be accomplished bymeans of a two part mould, one part of which is placed on one side ofthe blank of FIGURE 2 and the other part of which is placed on the otherside of the blank. When the two parts of the mould are pushed togetherthe arm 15 is bent to the desired shape.

The shaped blank is placed over the support plate with the bent arms 17entering into the socket. and each arm 15 is welded at 18 and 19 to itscorresponding metal strip 12. The outer ring 14 is then cut off to leaveeach arm 15 as an individual unit held in position on the support plate.

As shown in FIGURE 1 a cover plate 20 may be placed on the finishedsupport plate 10 and the cover plate will have sockets 21 correspondingto the sockets 11 so that the pins or wires of an electrical plug can bepushed through sockets 21 into the sockets 11. The spring arms 17 holdthe wires or pins in contact with the metal coatings on the insides ofthe sockets 11 and in addition themselves make contact with the wires orpins.

The cover plate 20 may be formed by etching in a similar way to thesupport plate 10 and the cover plate and the support 10 may be heldtogether by means of pins or rivets passing through holes 22 etched inthe support plate and the cover plate.

In use of the connector the support plate 10 is placed inside a matingsocket forming part of a printed circuit support or the like, and thestrips 12 are welded or soldered to corresponding connectionsin purposethere are notches 23 formed in the edges of the arms 15 so thatconnection can be made to the strips 12 directly.

FIGURE 3 shows a modified form of connector comprising a stack of foursupport plates 30. Each of the support plates 30 is formed in exactlythe same way as the the circuit. For this,

support plate 10 in the first embodiment, with the exception that eachsupport plate 30 has only some of its sockets 11 coated internally, withcorresponding metal strips 12 and arms 15. When the pins or wires of aplug are pushed into the connector of FIGURE 3 some of the pins willmake connection with the coated sockets in one support plate 30 andothers will make contact with coated sockets in another support plate30. Thus the ends of the metal strips 12 to be connected to an outsidecircuit are staggered at different levels in the stack for ease ofconnection.

The connector shown in FIGURE 3 may be provided with a base 31 withoutsocket holes and a cover plate 32 with holes 21.

FIGURE 4 shows a modified way in which the spring arms 15 may be bent.This form may be used in a connector (e.g. that of FIGURE 3) where thereare two stacked support plates 30 or more such plates as in FIG- URE 3.

It is not essential that the sockets be arranged in a ring. They may,for example, be in rows as seen in FIGURE 5 in which the sockets areshown at 30' and the pins of a plug contact are shown at 31. The contactstrips 32 extend to the edge of the support and are originally producedin the form of a grid as seen in FIGURE 6. Before attachment the arms ofthe grid are divided at the centre and the two parts bent downwardly andafter attachment the bars 33 are removed.

FIGURE 7 shows another form of connector adapted to receive a plug ofthe form shown in FIGURE 8. The connector body 35 shown in FIGURE 7 isof glass as above described and has a central aperture 37 to receive thebody 36 of the plug, the aperture being somewhat longer than the plug.Along each of the longer sides of the connector body there is a row ofstrips 38, 38a of metal coating on the body. The strips 38a on one sideof the body also extend down the side face. At the inner end of eachstrip the body has a notch 39 and adjacent the inner end there is arecess or hole 40. Welded or soldered to each strip there is a resilientcontact 42. These contacts, which are received between the recess 40 andthe outside edges of the body, have locating depressions 43 and tags 44which are secured in the recesses 40 and notches 3-9 (see FIGURE 9). Theside edges of the contacts are bent upwardly near the ends as seen at 45to provide lead-in ramps for the pins 46 of the plug which, as seen inFIGURE 10, are engaged under the ends of the contacts and between theseends and the underlying strips of metal coating. The ends of the row ofcontacts on one side of the body project in the plane of the uppersurface of the body as seen at 48 in FIGURE 9 and after insertion of thebody into a hole in a support panel 49 these ends are soldered to acircuit printed on the top surface of the panel. The ends of the otherrow of contacts are cranked downwardly, as shown at 50, to lie againstthe under surface of the panel and are secured to a circuit printed onthis surface. The contacts may be etched from a sheet in a manneranalogous to that shown in FIGURE 6 and the connecting ties cut ofiafter attachment. FIGURE 11 shows a portion of the unit after bending ofthe contacts and before removal of the tie 53.

The photo-sensitive glass and the photo-sensitive resist have beendescribed as being exposed through negatives and positives and it is tobe understood that the terms negatives and positives are intended toinclude metal masks as well as images on the normal photographic plates,films or other supports.

The invention may be applied to miniature switches in which there willbe a support of glass or other moulding material with one or moremetallic contacts coated thereon, with or without resilient contactsattached thereto, to receive in sliding or pressure contact, thecontacts of a companion switch member.

I claim:

1. An electrical socket connector, plug, switch or other electricalcontact device comprising a body of insulating material carrying atleast one electric contact provided by a metallic coating on the bodyand a separately constructed resilient contact secured to a metalliccoating on the body of insulating material, said first named metalliccoating and said resilient contact being arranged to make electricalconnection with opposite sides of a cooperating contact inserted betweenthem.

2. A device as claimed in claim 1 in which said second named metalliccoating is a part of said at least one metallic contact.

3. A device as claimed in claim 1 in which said second named metalliccoating is an extension of said at least one metallic contact.

4. An electrical socket connector as claimed in claim 1 in which saidbody has at least one socket and in which said resilient contactprojects into the socket.

5. An electrical socket connector as claimed in claim 1, in which saidbody is of glass with at least one socket formed therein, said socketbeing coated on its internal surface with metal to provide said at leastone metallic contact.

References Cited UNITED STATES PATENTS 2,248,718 7/1941 Owen 339 612,481,951 8/1949 Sabee 61. al. 156-150 2,692,305 10/1954 Mullin 179 1072,693,584 11/1954 Pifer 339-47 2,757,349 7/1956 Erbal 339-64 2,869,0401/1959 Pifer 339- 17 X 2,932,810 4/1960 Novak 339-17 2,953,765 9/1960Greasley 339-17 2,965,952 12/1960 Gillett et a1. 29- 155.55 2,973,4992/1961 Hammell ,339-17 3,011,379 12/196-1 Cor-win ,339-17X 3,061,911-11/1962- Baker.

3,177,103 4/1965 Tally et al. 339-17 X MARVIN A. CHAMPION, PrimaryExaminer. ALFRED S. TRASK, Examiner.

1. AN ELECTRICAL SOCKET CONNECTOR, PLUG, SWITCH OR OTHER ELECTRICALCONTACT DEVICE COMPRISING A BODY OF INSULATING MATERIAL CARRYING ATLEAST ONE ELECTRIC CONTACT PROVIDED BY A METALLIC COATING ON THE BODYAND A SEPARATELY CONSTRUCTED RESILIENT CONTACT SECURED TO A METALLICCOATING ON THE BODY OF INSULATING MATERIAL, SAID FIRST NAMED METALLICCOATING AND SAID RESILIENT CONTACT BEING ARRANGED TO MAKE ELECTRICALCONNECTION WITH OPPOSITE SIDES OF A COOPERATING CONTACT INSERTED BETWEENTHEM.